Page 32
4)Pressure Test for Water System
In order to ensure the water system is free of leakage, water pressure leak test should be carried out after unit
installation. During testing, the air vent can be used to release air trapped inside the water circuit (air trapped inside
the heat exchanger will produce excessive noise and will reduce the heat exchange efficiency). After all the trapped
air has been released, the air vent should be closed and water pressure to be increased gradually until the pre-defined
test pressure. Subsequently, check for water leakage at joints.
Caution: The leak test should not be carried out under freezing condition (lowest temperature > 0
°
C).
Otherwise, after pressure test water must be drained out completely and anti-freeze procedure must be
adopted to prevent breakage of water pipes due to freezing.
When system is not operated during winter, the water in the system must be drained out completely and
anti-freeze procedure must be adopted to prevent breakage of water pipes due to freezing.
5
)
Pre-Operation Inspection
Before the unit is ready for operation, the following check should be carried out:
a) Unit has been installed according to manufacturer specifications and the condensate water drainage pipe is not
blocked.
b) Ensure no debris in drain pan, blower and casing.
c) Unit’s power supply and controls are properly connected and unit is properly GROUNDED.
d) Water piping is properly connected and no leakage found.
e) Blowers are free to turn and filter properly installed.
f) All the pipes are insulated, valves are opened and air vent is closed.
